Authorities still have no idea where the missing Malaysia Airlines plane is, but they've found a new place to refocus their efforts—the pilot who said, "All right, good night," a few minutes after the plane was diverted.

The plane made a sharp, deliberate turn just after it last communicated with Kuala Lumpur air traffic controllers, and before it would have to communicate with Vietnamese controllers, according to the U.S. official with knowledge of the latest intelligence thinking.

The authorities may also be looking at an aviation engineer who was among the passengers. The New Straits Times, a newspaper published in Malaysia, interviewed a man who said that his son, an aircraft engineer, had been on the flight en route to China to work on Malaysia Airlines planes.

Officials from 25 countries are now participating in the search, which has yielded scant clues since the plane went missing last Saturday.